Platinum resistance temperature probe
Aslec
are welded These RTD's have a low ohmic value
(see corresponding heading) and the lead length
presents a resistance in serie with the sensitive
element which harms the measurement accuracy.
To avoid such reaction, 3 or 4 leads are used so as to separate
the measurements leads from the feeding leads, thus, the
measurement leads will not be supporting a current and their
own resistance will be negligible.
Probes with Platinum or Nickel sensors are connected to
electronics for measurement, data or automation by means
of a 4-20 milli Amp. Transmitter (the most suitable solution)
or a 0-10 V. or 0-5 V. voltage transmitter.
It is strongly advised to place the transmitter as closed as
possible from the sensor to avoid RFI in the leads
